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XELK-AN-008: How to use systemd on an Embedded system

22 bytes removed, 21:00, 24 September 2019
Putting it all together: create a new service
systemctl enable wpa_supplicant@wlan0
=== Logging with systemd (<code>journalctl</code>) ===
systemd has its own logging process called <code>journal</code> avoiding to start the ''syslog'' daemon. For the status information it is possible to use <code>journalctl</code>.
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=== Analyze the boot time===
Boot time analysis is one of the most important and interesting activity for an embedded system: systemd provide an userspace command called <code>systemd-analyze</code> to help in this (hard) task
<code>systemd-analyze</code> provides a good level of boot time information for further optimizations:
==== time ====
The <code>time</code> parameter gives the total amount of seconds used for starting the kernel and reaching the userspace.
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==== blame ====
The <code>blame</code> parameter gives the list of started services and how long they took for starting:
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==== critical-chain ====
The <code>critical-chain</code> parameter shows the startup process flow and the time consumed by each service.
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=== Putting it all together: create a new service ===
For creating a new service the following file has to be created:
/etc/systemd/system/''<service_name>''.service
==== Service example ====
The following paragraph shows how to create a new service called <code>iperf3</code> executing the iperf3 command in server mode
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===== Basic settings =====
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===== Running a service =====
Starting the service from userspace:
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